// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/* Copyright 2020-2021 NXP
 */
#include <net/devlink.h>
#include "ocelot.h"

/* The queue system tracks four resource consumptions:
 * Resource 0: Memory tracked per source port
 * Resource 1: Frame references tracked per source port
 * Resource 2: Memory tracked per destination port
 * Resource 3: Frame references tracked per destination port
 */
#define OCELOT_RESOURCE_SZ              256
#define OCELOT_NUM_RESOURCES            4

#define BUF_xxxx_I                      (0 * OCELOT_RESOURCE_SZ)
#define REF_xxxx_I                      (1 * OCELOT_RESOURCE_SZ)
#define BUF_xxxx_E                      (2 * OCELOT_RESOURCE_SZ)
#define REF_xxxx_E                      (3 * OCELOT_RESOURCE_SZ)

/* For each resource type there are 4 types of watermarks:
 * Q_RSRV: reservation per QoS class per port
 * PRIO_SHR: sharing watermark per QoS class across all ports
 * P_RSRV: reservation per port
 * COL_SHR: sharing watermark per color (drop precedence) across all ports
 */
#define xxx_Q_RSRV_x                    0
#define xxx_PRIO_SHR_x                  216
#define xxx_P_RSRV_x                    224
#define xxx_COL_SHR_x                   254

/* Reservation Watermarks
 * ----------------------
 *
 * For setting up the reserved areas, egress watermarks exist per port and per
 * QoS class for both ingress and egress.
 */

/*  Amount of packet buffer
 *  |  per QoS class
 *  |  |  reserved
 *  |  |  |   per egress port
 *  |  |  |   |
 *  V  V  v   v
 * BUF_Q_RSRV_E
 */
#define BUF_Q_RSRV_E(port, prio) \
        (BUF_xxxx_E + xxx_Q_RSRV_x + OCELOT_NUM_TC * (port) + (prio))

/*  Amount of packet buffer
 *  |  for all port's traffic classes
 *  |  |  reserved
 *  |  |  |   per egress port
 *  |  |  |   |
 *  V  V  v   v
 * BUF_P_RSRV_E
 */
#define BUF_P_RSRV_E(port) \
        (BUF_xxxx_E + xxx_P_RSRV_x + (port))

/*  Amount of packet buffer
 *  |  per QoS class
 *  |  |  reserved
 *  |  |  |   per ingress port
 *  |  |  |   |
 *  V  V  v   v
 * BUF_Q_RSRV_I
 */
#define BUF_Q_RSRV_I(port, prio) \
        (BUF_xxxx_I + xxx_Q_RSRV_x + OCELOT_NUM_TC * (port) + (prio))

/*  Amount of packet buffer
 *  |  for all port's traffic classes
 *  |  |  reserved
 *  |  |  |   per ingress port
 *  |  |  |   |
 *  V  V  v   v
 * BUF_P_RSRV_I
 */
#define BUF_P_RSRV_I(port) \
        (BUF_xxxx_I + xxx_P_RSRV_x + (port))

/*  Amount of frame references
 *  |  per QoS class
 *  |  |  reserved
 *  |  |  |   per egress port
 *  |  |  |   |
 *  V  V  v   v
 * REF_Q_RSRV_E
 */
#define REF_Q_RSRV_E(port, prio) \
        (REF_xxxx_E + xxx_Q_RSRV_x + OCELOT_NUM_TC * (port) + (prio))

/*  Amount of frame references
 *  |  for all port's traffic classes
 *  |  |  reserved
 *  |  |  |   per egress port
 *  |  |  |   |
 *  V  V  v   v
 * REF_P_RSRV_E
 */
#define REF_P_RSRV_E(port) \
        (REF_xxxx_E + xxx_P_RSRV_x + (port))

/*  Amount of frame references
 *  |  per QoS class
 *  |  |  reserved
 *  |  |  |   per ingress port
 *  |  |  |   |
 *  V  V  v   v
 * REF_Q_RSRV_I
 */
#define REF_Q_RSRV_I(port, prio) \
        (REF_xxxx_I + xxx_Q_RSRV_x + OCELOT_NUM_TC * (port) + (prio))

/*  Amount of frame references
 *  |  for all port's traffic classes
 *  |  |  reserved
 *  |  |  |   per ingress port
 *  |  |  |   |
 *  V  V  v   v
 * REF_P_RSRV_I
 */
#define REF_P_RSRV_I(port) \
        (REF_xxxx_I + xxx_P_RSRV_x + (port))

/* Sharing Watermarks
 * ------------------
 *
 * The shared memory area is shared between all ports.
 */

/* Amount of buffer
 *  |   per QoS class
 *  |   |    from the shared memory area
 *  |   |    |  for egress traffic
 *  |   |    |  |
 *  V   V    v  v
 * BUF_PRIO_SHR_E
 */
#define BUF_PRIO_SHR_E(prio) \
        (BUF_xxxx_E + xxx_PRIO_SHR_x + (prio))

/* Amount of buffer
 *  |   per color (drop precedence level)
 *  |   |   from the shared memory area
 *  |   |   |  for egress traffic
 *  |   |   |  |
 *  V   V   v  v
 * BUF_COL_SHR_E
 */
#define BUF_COL_SHR_E(dp) \
        (BUF_xxxx_E + xxx_COL_SHR_x + (1 - (dp)))

/* Amount of buffer
 *  |   per QoS class
 *  |   |    from the shared memory area
 *  |   |    |  for ingress traffic
 *  |   |    |  |
 *  V   V    v  v
 * BUF_PRIO_SHR_I
 */
#define BUF_PRIO_SHR_I(prio) \
        (BUF_xxxx_I + xxx_PRIO_SHR_x + (prio))

/* Amount of buffer
 *  |   per color (drop precedence level)
 *  |   |   from the shared memory area
 *  |   |   |  for ingress traffic
 *  |   |   |  |
 *  V   V   v  v
 * BUF_COL_SHR_I
 */
#define BUF_COL_SHR_I(dp) \
        (BUF_xxxx_I + xxx_COL_SHR_x + (1 - (dp)))

/* Amount of frame references
 *  |   per QoS class
 *  |   |    from the shared area
 *  |   |    |  for egress traffic
 *  |   |    |  |
 *  V   V    v  v
 * REF_PRIO_SHR_E
 */
#define REF_PRIO_SHR_E(prio) \
        (REF_xxxx_E + xxx_PRIO_SHR_x + (prio))

/* Amount of frame references
 *  |   per color (drop precedence level)
 *  |   |   from the shared area
 *  |   |   |  for egress traffic
 *  |   |   |  |
 *  V   V   v  v
 * REF_COL_SHR_E
 */
#define REF_COL_SHR_E(dp) \
        (REF_xxxx_E + xxx_COL_SHR_x + (1 - (dp)))

/* Amount of frame references
 *  |   per QoS class
 *  |   |    from the shared area
 *  |   |    |  for ingress traffic
 *  |   |    |  |
 *  V   V    v  v
 * REF_PRIO_SHR_I
 */
#define REF_PRIO_SHR_I(prio) \
        (REF_xxxx_I + xxx_PRIO_SHR_x + (prio))

/* Amount of frame references
 *  |   per color (drop precedence level)
 *  |   |   from the shared area
 *  |   |   |  for ingress traffic
 *  |   |   |  |
 *  V   V   v  v
 * REF_COL_SHR_I
 */
#define REF_COL_SHR_I(dp) \
        (REF_xxxx_I + xxx_COL_SHR_x + (1 - (dp)))

static u32 ocelot_wm_read(struct ocelot *ocelot, int index)
{
        int wm = ocelot_read_gix(ocelot, QSYS_RES_CFG, index);

        return ocelot->ops->wm_dec(wm);
}

static void ocelot_wm_write(struct ocelot *ocelot, int index, u32 val)
{
        u32 wm = ocelot->ops->wm_enc(val);

        ocelot_write_gix(ocelot, wm, QSYS_RES_CFG, index);
}

static void ocelot_wm_status(struct ocelot *ocelot, int index, u32 *inuse,
                             u32 *maxuse)
{
        int res_stat = ocelot_read_gix(ocelot, QSYS_RES_STAT, index);

        return ocelot->ops->wm_stat(res_stat, inuse, maxuse);
}

/* The hardware comes out of reset with strange defaults: the sum of all
 * reservations for frame memory is larger than the total buffer size.
 * One has to wonder how can the reservation watermarks still guarantee
 * anything under congestion.
 * Bring some sense into the hardware by changing the defaults to disable all
 * reservations and rely only on the sharing watermark for frames with drop
 * precedence 0. The user can still explicitly request reservations per port
 * and per port-tc through devlink-sb.
 */
static void ocelot_disable_reservation_watermarks(struct ocelot *ocelot,
                                                  int port)
{
        int prio;

        for (prio = 0; prio < OCELOT_NUM_TC; prio++) {
                ocelot_wm_write(ocelot, BUF_Q_RSRV_I(port, prio), 0);
                ocelot_wm_write(ocelot, BUF_Q_RSRV_E(port, prio), 0);
                ocelot_wm_write(ocelot, REF_Q_RSRV_I(port, prio), 0);
                ocelot_wm_write(ocelot, REF_Q_RSRV_E(port, prio), 0);
        }

        ocelot_wm_write(ocelot, BUF_P_RSRV_I(port), 0);
        ocelot_wm_write(ocelot, BUF_P_RSRV_E(port), 0);
        ocelot_wm_write(ocelot, REF_P_RSRV_I(port), 0);
        ocelot_wm_write(ocelot, REF_P_RSRV_E(port), 0);
}

/* We want the sharing watermarks to consume all nonreserved resources, for
 * efficient resource utilization (a single traffic flow should be able to use
 * up the entire buffer space and frame resources as long as there's no
 * interference).
 * The switch has 10 sharing watermarks per lookup: 8 per traffic class and 2
 * per color (drop precedence).
 * The trouble with configuring these sharing watermarks is that:
 * (1) There's a risk that we overcommit the resources if we configure
 *     (a) all 8 per-TC sharing watermarks to the max
 *     (b) all 2 per-color sharing watermarks to the max
 * (2) There's a risk that we undercommit the resources if we configure
 *     (a) all 8 per-TC sharing watermarks to "max / 8"
 *     (b) all 2 per-color sharing watermarks to "max / 2"
 * So for Linux, let's just disable the sharing watermarks per traffic class
 * (setting them to 0 will make them always exceeded), and rely only on the
 * sharing watermark for drop priority 0. So frames with drop priority set to 1
 * by QoS classification or policing will still be allowed, but only as long as
 * the port and port-TC reservations are not exceeded.
 */
static void ocelot_disable_tc_sharing_watermarks(struct ocelot *ocelot)
{
        int prio;

        for (prio = 0; prio < OCELOT_NUM_TC; prio++) {
                ocelot_wm_write(ocelot, BUF_PRIO_SHR_I(prio), 0);
                ocelot_wm_write(ocelot, BUF_PRIO_SHR_E(prio), 0);
                ocelot_wm_write(ocelot, REF_PRIO_SHR_I(prio), 0);
                ocelot_wm_write(ocelot, REF_PRIO_SHR_E(prio), 0);
        }
}

static void ocelot_get_buf_rsrv(struct ocelot *ocelot, u32 *buf_rsrv_i,
                                u32 *buf_rsrv_e)
{
        int port, prio;

        *buf_rsrv_i = 0;
        *buf_rsrv_e = 0;

        for (port = 0; port <= ocelot->num_phys_ports; port++) {
                for (prio = 0; prio < OCELOT_NUM_TC; prio++) {
                        *buf_rsrv_i += ocelot_wm_read(ocelot,
                                                      BUF_Q_RSRV_I(port, prio));
                        *buf_rsrv_e += ocelot_wm_read(ocelot,
                                                      BUF_Q_RSRV_E(port, prio));
                }

                *buf_rsrv_i += ocelot_wm_read(ocelot, BUF_P_RSRV_I(port));
                *buf_rsrv_e += ocelot_wm_read(ocelot, BUF_P_RSRV_E(port));
        }

        *buf_rsrv_i *= OCELOT_BUFFER_CELL_SZ;
        *buf_rsrv_e *= OCELOT_BUFFER_CELL_SZ;
}

static void ocelot_get_ref_rsrv(struct ocelot *ocelot, u32 *ref_rsrv_i,
                                u32 *ref_rsrv_e)
{
        int port, prio;

        *ref_rsrv_i = 0;
        *ref_rsrv_e = 0;

        for (port = 0; port <= ocelot->num_phys_ports; port++) {
                for (prio = 0; prio < OCELOT_NUM_TC; prio++) {
                        *ref_rsrv_i += ocelot_wm_read(ocelot,
                                                      REF_Q_RSRV_I(port, prio));
                        *ref_rsrv_e += ocelot_wm_read(ocelot,
                                                      REF_Q_RSRV_E(port, prio));
                }

                *ref_rsrv_i += ocelot_wm_read(ocelot, REF_P_RSRV_I(port));
                *ref_rsrv_e += ocelot_wm_read(ocelot, REF_P_RSRV_E(port));
        }
}

/* Calculate all reservations, then set up the sharing watermark for DP=0 to
 * consume the remaining resources up to the pool's configured size.
 */
static void ocelot_setup_sharing_watermarks(struct ocelot *ocelot)
{
        u32 buf_rsrv_i, buf_rsrv_e;
        u32 ref_rsrv_i, ref_rsrv_e;
        u32 buf_shr_i, buf_shr_e;
        u32 ref_shr_i, ref_shr_e;

        ocelot_get_buf_rsrv(ocelot, &buf_rsrv_i, &buf_rsrv_e);
        ocelot_get_ref_rsrv(ocelot, &ref_rsrv_i, &ref_rsrv_e);

        buf_shr_i = ocelot->pool_size[OCELOT_SB_BUF][OCELOT_SB_POOL_ING] -
                    buf_rsrv_i;
        buf_shr_e = ocelot->pool_size[OCELOT_SB_BUF][OCELOT_SB_POOL_EGR] -
                    buf_rsrv_e;
        ref_shr_i = ocelot->pool_size[OCELOT_SB_REF][OCELOT_SB_POOL_ING] -
                    ref_rsrv_i;
        ref_shr_e = ocelot->pool_size[OCELOT_SB_REF][OCELOT_SB_POOL_EGR] -
                    ref_rsrv_e;

        buf_shr_i /= OCELOT_BUFFER_CELL_SZ;
        buf_shr_e /= OCELOT_BUFFER_CELL_SZ;

        ocelot_wm_write(ocelot, BUF_COL_SHR_I(0), buf_shr_i);
        ocelot_wm_write(ocelot, BUF_COL_SHR_E(0), buf_shr_e);
        ocelot_wm_write(ocelot, REF_COL_SHR_E(0), ref_shr_e);
        ocelot_wm_write(ocelot, REF_COL_SHR_I(0), ref_shr_i);
        ocelot_wm_write(ocelot, BUF_COL_SHR_I(1), 0);
        ocelot_wm_write(ocelot, BUF_COL_SHR_E(1), 0);
        ocelot_wm_write(ocelot, REF_COL_SHR_E(1), 0);
        ocelot_wm_write(ocelot, REF_COL_SHR_I(1), 0);
}

/* Ensure that all reservations can be enforced */
static int ocelot_watermark_validate(struct ocelot *ocelot,
                                     struct netlink_ext_ack *extack)
{
        u32 buf_rsrv_i, buf_rsrv_e;
        u32 ref_rsrv_i, ref_rsrv_e;

        ocelot_get_buf_rsrv(ocelot, &buf_rsrv_i, &buf_rsrv_e);
        ocelot_get_ref_rsrv(ocelot, &ref_rsrv_i, &ref_rsrv_e);

        if (buf_rsrv_i > ocelot->pool_size[OCELOT_SB_BUF][OCELOT_SB_POOL_ING]) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Ingress frame reservations exceed pool size");
                return -ERANGE;
        }
        if (buf_rsrv_e > ocelot->pool_size[OCELOT_SB_BUF][OCELOT_SB_POOL_EGR]) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Egress frame reservations exceed pool size");
                return -ERANGE;
        }
        if (ref_rsrv_i > ocelot->pool_size[OCELOT_SB_REF][OCELOT_SB_POOL_ING]) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Ingress reference reservations exceed pool size");
                return -ERANGE;
        }
        if (ref_rsrv_e > ocelot->pool_size[OCELOT_SB_REF][OCELOT_SB_POOL_EGR]) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Egress reference reservations exceed pool size");
                return -ERANGE;
        }

        return 0;
}

/* The hardware works like this:
 *
 *                         Frame forwarding decision taken
 *                                       |
 *                                       v
 *       +--------------------+--------------------+--------------------+
 *       |                    |                    |                    |
 *       v                    v                    v                    v
 * Ingress memory       Egress memory        Ingress frame        Egress frame
 *     check                check           reference check      reference check
 *       |                    |                    |                    |
 *       v                    v                    v                    v
 *  BUF_Q_RSRV_I   ok    BUF_Q_RSRV_E   ok    REF_Q_RSRV_I   ok     REF_Q_RSRV_E   ok
 *(src port, prio) -+  (dst port, prio) -+  (src port, prio) -+   (dst port, prio) -+
 *       |          |         |          |         |          |         |           |
 *       |exceeded  |         |exceeded  |         |exceeded  |         |exceeded   |
 *       v          |         v          |         v          |         v           |
 *  BUF_P_RSRV_I  ok|    BUF_P_RSRV_E  ok|    REF_P_RSRV_I  ok|    REF_P_RSRV_E   ok|
 *   (src port) ----+     (dst port) ----+     (src port) ----+     (dst port) -----+
 *       |          |         |          |         |          |         |           |
 *       |exceeded  |         |exceeded  |         |exceeded  |         |exceeded   |
 *       v          |         v          |         v          |         v           |
 * BUF_PRIO_SHR_I ok|   BUF_PRIO_SHR_E ok|   REF_PRIO_SHR_I ok|   REF_PRIO_SHR_E  ok|
 *     (prio) ------+       (prio) ------+       (prio) ------+       (prio) -------+
 *       |          |         |          |         |          |         |           |
 *       |exceeded  |         |exceeded  |         |exceeded  |         |exceeded   |
 *       v          |         v          |         v          |         v           |
 * BUF_COL_SHR_I  ok|   BUF_COL_SHR_E  ok|   REF_COL_SHR_I  ok|   REF_COL_SHR_E   ok|
 *      (dp) -------+        (dp) -------+        (dp) -------+        (dp) --------+
 *       |          |         |          |         |          |         |           |
 *       |exceeded  |         |exceeded  |         |exceeded  |         |exceeded   |
 *       v          v         v          v         v          v         v           v
 *      fail     success     fail     success     fail     success     fail      success
 *       |          |         |          |         |          |         |           |
 *       v          v         v          v         v          v         v           v
 *       +-----+----+         +-----+----+         +-----+----+         +-----+-----+
 *             |                    |                    |                    |
 *             +-------> OR <-------+                    +-------> OR <-------+
 *                        |                                        |
 *                        v                                        v
 *                        +----------------> AND <-----------------+
 *                                            |
 *                                            v
 *                                    FIFO drop / accept
 *
 * We are modeling each of the 4 parallel lookups as a devlink-sb pool.
 * At least one (ingress or egress) memory pool and one (ingress or egress)
 * frame reference pool need to have resources for frame acceptance to succeed.
 *
 * The following watermarks are controlled explicitly through devlink-sb:
 * BUF_Q_RSRV_I, BUF_Q_RSRV_E, REF_Q_RSRV_I, REF_Q_RSRV_E
 * BUF_P_RSRV_I, BUF_P_RSRV_E, REF_P_RSRV_I, REF_P_RSRV_E
 * The following watermarks are controlled implicitly through devlink-sb:
 * BUF_COL_SHR_I, BUF_COL_SHR_E, REF_COL_SHR_I, REF_COL_SHR_E
 * The following watermarks are unused and disabled:
 * BUF_PRIO_SHR_I, BUF_PRIO_SHR_E, REF_PRIO_SHR_I, REF_PRIO_SHR_E
 *
 * This function overrides the hardware defaults with more sane ones (no
 * reservations by default, let sharing use all resources) and disables the
 * unused watermarks.
 */
static void ocelot_watermark_init(struct ocelot *ocelot)
{
        int all_tcs = GENMASK(OCELOT_NUM_TC - 1, 0);
        int port;

        ocelot_write(ocelot, all_tcs, QSYS_RES_QOS_MODE);

        for (port = 0; port <= ocelot->num_phys_ports; port++)
                ocelot_disable_reservation_watermarks(ocelot, port);

        ocelot_disable_tc_sharing_watermarks(ocelot);
        ocelot_setup_sharing_watermarks(ocelot);
}

/* Watermark encode
 * Bit 8:   Unit; 0:1, 1:16
 * Bit 7-0: Value to be multiplied with unit
 */
u16 ocelot_wm_enc(u16 value)
{
        WARN_ON(value >= 16 * BIT(8));

        if (value >= BIT(8))
                return BIT(8) | (value / 16);

        return value;
}
EXPORT_SYMBOL(ocelot_wm_enc);

u16 ocelot_wm_dec(u16 wm)
{
        if (wm & BIT(8))
                return (wm & GENMASK(7, 0)) * 16;

        return wm;
}
EXPORT_SYMBOL(ocelot_wm_dec);

void ocelot_wm_stat(u32 val, u32 *inuse, u32 *maxuse)
{
        *inuse = (val & GENMASK(23, 12)) >> 12;
        *maxuse = val & GENMASK(11, 0);
}
EXPORT_SYMBOL(ocelot_wm_stat);

/* Pool size and type are fixed up at runtime. Keeping this structure to
 * look up the cell size multipliers.
 */
static const struct devlink_sb_pool_info ocelot_sb_pool[] = {
        [OCELOT_SB_BUF] = {
                .cell_size = OCELOT_BUFFER_CELL_SZ,
                .threshold_type = DEVLINK_SB_THRESHOLD_TYPE_STATIC,
        },
        [OCELOT_SB_REF] = {
                .cell_size = 1,
                .threshold_type = DEVLINK_SB_THRESHOLD_TYPE_STATIC,
        },
};

/* Returns the pool size configured through ocelot_sb_pool_set */
int ocelot_sb_pool_get(struct ocelot *ocelot, unsigned int sb_index,
                       u16 pool_index,
                       struct devlink_sb_pool_info *pool_info)
{
        if (sb_index >= OCELOT_SB_NUM)
                return -ENODEV;
        if (pool_index >= OCELOT_SB_POOL_NUM)
                return -ENODEV;

        *pool_info = ocelot_sb_pool[sb_index];
        pool_info->size = ocelot->pool_size[sb_index][pool_index];
        if (pool_index)
                pool_info->pool_type = DEVLINK_SB_POOL_TYPE_INGRESS;
        else
                pool_info->pool_type = DEVLINK_SB_POOL_TYPE_EGRESS;

        return 0;
}
EXPORT_SYMBOL(ocelot_sb_pool_get);

/* The pool size received here configures the total amount of resources used on
 * ingress (or on egress, depending upon the pool index). The pool size, minus
 * the values for the port and port-tc reservations, is written into the
 * COL_SHR(dp=0) sharing watermark.
 */
int ocelot_sb_pool_set(struct ocelot *ocelot, unsigned int sb_index,
                       u16 pool_index, u32 size,
                       enum devlink_sb_threshold_type threshold_type,
                       struct netlink_ext_ack *extack)
{
        u32 old_pool_size;
        int err;

        if (sb_index >= OCELOT_SB_NUM) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Invalid sb, use 0 for buffers and 1 for frame references");
                return -ENODEV;
        }
        if (pool_index >= OCELOT_SB_POOL_NUM) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Invalid pool, use 0 for ingress and 1 for egress");
                return -ENODEV;
        }
        if (threshold_type != DEVLINK_SB_THRESHOLD_TYPE_STATIC) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Only static threshold supported");
                return -EOPNOTSUPP;
        }

        old_pool_size = ocelot->pool_size[sb_index][pool_index];
        ocelot->pool_size[sb_index][pool_index] = size;

        err = ocelot_watermark_validate(ocelot, extack);
        if (err) {
                ocelot->pool_size[sb_index][pool_index] = old_pool_size;
                return err;
        }

        ocelot_setup_sharing_watermarks(ocelot);

        return 0;
}
EXPORT_SYMBOL(ocelot_sb_pool_set);

/* This retrieves the configuration made with ocelot_sb_port_pool_set */
int ocelot_sb_port_pool_get(struct ocelot *ocelot, int port,
                            unsigned int sb_index, u16 pool_index,
                            u32 *p_threshold)
{
        int wm_index;

        switch (sb_index) {
        case OCELOT_SB_BUF:
                if (pool_index == OCELOT_SB_POOL_ING)
                        wm_index = BUF_P_RSRV_I(port);
                else
                        wm_index = BUF_P_RSRV_E(port);
                break;
        case OCELOT_SB_REF:
                if (pool_index == OCELOT_SB_POOL_ING)
                        wm_index = REF_P_RSRV_I(port);
                else
                        wm_index = REF_P_RSRV_E(port);
                break;
        default:
                return -ENODEV;
        }

        *p_threshold = ocelot_wm_read(ocelot, wm_index);
        *p_threshold *= ocelot_sb_pool[sb_index].cell_size;

        return 0;
}
EXPORT_SYMBOL(ocelot_sb_port_pool_get);

/* This configures the P_RSRV per-port reserved resource watermark */
int ocelot_sb_port_pool_set(struct ocelot *ocelot, int port,
                            unsigned int sb_index, u16 pool_index,
                            u32 threshold, struct netlink_ext_ack *extack)
{
        int wm_index, err;
        u32 old_thr;

        switch (sb_index) {
        case OCELOT_SB_BUF:
                if (pool_index == OCELOT_SB_POOL_ING)
                        wm_index = BUF_P_RSRV_I(port);
                else
                        wm_index = BUF_P_RSRV_E(port);
                break;
        case OCELOT_SB_REF:
                if (pool_index == OCELOT_SB_POOL_ING)
                        wm_index = REF_P_RSRV_I(port);
                else
                        wm_index = REF_P_RSRV_E(port);
                break;
        default:
                NL_SET_ERR_MSG_MOD(extack, "Invalid shared buffer");
                return -ENODEV;
        }

        threshold /= ocelot_sb_pool[sb_index].cell_size;

        old_thr = ocelot_wm_read(ocelot, wm_index);
        ocelot_wm_write(ocelot, wm_index, threshold);

        err = ocelot_watermark_validate(ocelot, extack);
        if (err) {
                ocelot_wm_write(ocelot, wm_index, old_thr);
                return err;
        }

        ocelot_setup_sharing_watermarks(ocelot);

        return 0;
}
EXPORT_SYMBOL(ocelot_sb_port_pool_set);

/* This retrieves the configuration done by ocelot_sb_tc_pool_bind_set */
int ocelot_sb_tc_pool_bind_get(struct ocelot *ocelot, int port,
                               unsigned int sb_index, u16 tc_index,
                               enum devlink_sb_pool_type pool_type,
                               u16 *p_pool_index, u32 *p_threshold)
{
        int wm_index;

        switch (sb_index) {
        case OCELOT_SB_BUF:
                if (pool_type == DEVLINK_SB_POOL_TYPE_INGRESS)
                        wm_index = BUF_Q_RSRV_I(port, tc_index);
                else
                        wm_index = BUF_Q_RSRV_E(port, tc_index);
                break;
        case OCELOT_SB_REF:
                if (pool_type == DEVLINK_SB_POOL_TYPE_INGRESS)
                        wm_index = REF_Q_RSRV_I(port, tc_index);
                else
                        wm_index = REF_Q_RSRV_E(port, tc_index);
                break;
        default:
                return -ENODEV;
        }

        *p_threshold = ocelot_wm_read(ocelot, wm_index);
        *p_threshold *= ocelot_sb_pool[sb_index].cell_size;

        if (pool_type == DEVLINK_SB_POOL_TYPE_INGRESS)
                *p_pool_index = 0;
        else
                *p_pool_index = 1;

        return 0;
}
EXPORT_SYMBOL(ocelot_sb_tc_pool_bind_get);

/* This configures the Q_RSRV per-port-tc reserved resource watermark */
int ocelot_sb_tc_pool_bind_set(struct ocelot *ocelot, int port,
                               unsigned int sb_index, u16 tc_index,
                               enum devlink_sb_pool_type pool_type,
                               u16 pool_index, u32 threshold,
                               struct netlink_ext_ack *extack)
{
        int wm_index, err;
        u32 old_thr;

        /* Paranoid check? */
        if (pool_index == OCELOT_SB_POOL_ING &&
            pool_type != DEVLINK_SB_POOL_TYPE_INGRESS)
                return -EINVAL;
        if (pool_index == OCELOT_SB_POOL_EGR &&
            pool_type != DEVLINK_SB_POOL_TYPE_EGRESS)
                return -EINVAL;

        switch (sb_index) {
        case OCELOT_SB_BUF:
                if (pool_type == DEVLINK_SB_POOL_TYPE_INGRESS)
                        wm_index = BUF_Q_RSRV_I(port, tc_index);
                else
                        wm_index = BUF_Q_RSRV_E(port, tc_index);
                break;
        case OCELOT_SB_REF:
                if (pool_type == DEVLINK_SB_POOL_TYPE_INGRESS)
                        wm_index = REF_Q_RSRV_I(port, tc_index);
                else
                        wm_index = REF_Q_RSRV_E(port, tc_index);
                break;
        default:
                NL_SET_ERR_MSG_MOD(extack, "Invalid shared buffer");
                return -ENODEV;
        }

        threshold /= ocelot_sb_pool[sb_index].cell_size;

        old_thr = ocelot_wm_read(ocelot, wm_index);
        ocelot_wm_write(ocelot, wm_index, threshold);
        err = ocelot_watermark_validate(ocelot, extack);
        if (err) {
                ocelot_wm_write(ocelot, wm_index, old_thr);
                return err;
        }

        ocelot_setup_sharing_watermarks(ocelot);

        return 0;
}
EXPORT_SYMBOL(ocelot_sb_tc_pool_bind_set);

/* The hardware does not support atomic snapshots, we'll read out the
 * occupancy registers individually and have this as just a stub.
 */
int ocelot_sb_occ_snapshot(struct ocelot *ocelot, unsigned int sb_index)
{
        return 0;
}
EXPORT_SYMBOL(ocelot_sb_occ_snapshot);

/* The watermark occupancy registers are cleared upon read,
 * so let's read them.
 */
int ocelot_sb_occ_max_clear(struct ocelot *ocelot, unsigned int sb_index)
{
        u32 inuse, maxuse;
        int port, prio;

        switch (sb_index) {
        case OCELOT_SB_BUF:
                for (port = 0; port <= ocelot->num_phys_ports; port++) {
                        for (prio = 0; prio < OCELOT_NUM_TC; prio++) {
                                ocelot_wm_status(ocelot, BUF_Q_RSRV_I(port, prio),
                                                 &inuse, &maxuse);
                                ocelot_wm_status(ocelot, BUF_Q_RSRV_E(port, prio),
                                                 &inuse, &maxuse);
                        }
                        ocelot_wm_status(ocelot, BUF_P_RSRV_I(port),
                                         &inuse, &maxuse);
                        ocelot_wm_status(ocelot, BUF_P_RSRV_E(port),
                                         &inuse, &maxuse);
                }
                break;
        case OCELOT_SB_REF:
                for (port = 0; port <= ocelot->num_phys_ports; port++) {
                        for (prio = 0; prio < OCELOT_NUM_TC; prio++) {
                                ocelot_wm_status(ocelot, REF_Q_RSRV_I(port, prio),
                                                 &inuse, &maxuse);
                                ocelot_wm_status(ocelot, REF_Q_RSRV_E(port, prio),
                                                 &inuse, &maxuse);
                        }
                        ocelot_wm_status(ocelot, REF_P_RSRV_I(port),
                                         &inuse, &maxuse);
                        ocelot_wm_status(ocelot, REF_P_RSRV_E(port),
                                         &inuse, &maxuse);
                }
                break;
        default:
                return -ENODEV;
        }

        return 0;
}
EXPORT_SYMBOL(ocelot_sb_occ_max_clear);

/* This retrieves the watermark occupancy for per-port P_RSRV watermarks */
int ocelot_sb_occ_port_pool_get(struct ocelot *ocelot, int port,
                                unsigned int sb_index, u16 pool_index,
                                u32 *p_cur, u32 *p_max)
{
        int wm_index;

        switch (sb_index) {
        case OCELOT_SB_BUF:
                if (pool_index == OCELOT_SB_POOL_ING)
                        wm_index = BUF_P_RSRV_I(port);
                else
                        wm_index = BUF_P_RSRV_E(port);
                break;
        case OCELOT_SB_REF:
                if (pool_index == OCELOT_SB_POOL_ING)
                        wm_index = REF_P_RSRV_I(port);
                else
                        wm_index = REF_P_RSRV_E(port);
                break;
        default:
                return -ENODEV;
        }

        ocelot_wm_status(ocelot, wm_index, p_cur, p_max);
        *p_cur *= ocelot_sb_pool[sb_index].cell_size;
        *p_max *= ocelot_sb_pool[sb_index].cell_size;

        return 0;
}
EXPORT_SYMBOL(ocelot_sb_occ_port_pool_get);

/* This retrieves the watermark occupancy for per-port-tc Q_RSRV watermarks */
int ocelot_sb_occ_tc_port_bind_get(struct ocelot *ocelot, int port,
                                   unsigned int sb_index, u16 tc_index,
                                   enum devlink_sb_pool_type pool_type,
                                   u32 *p_cur, u32 *p_max)
{
        int wm_index;

        switch (sb_index) {
        case OCELOT_SB_BUF:
                if (pool_type == DEVLINK_SB_POOL_TYPE_INGRESS)
                        wm_index = BUF_Q_RSRV_I(port, tc_index);
                else
                        wm_index = BUF_Q_RSRV_E(port, tc_index);
                break;
        case OCELOT_SB_REF:
                if (pool_type == DEVLINK_SB_POOL_TYPE_INGRESS)
                        wm_index = REF_Q_RSRV_I(port, tc_index);
                else
                        wm_index = REF_Q_RSRV_E(port, tc_index);
                break;
        default:
                return -ENODEV;
        }

        ocelot_wm_status(ocelot, wm_index, p_cur, p_max);
        *p_cur *= ocelot_sb_pool[sb_index].cell_size;
        *p_max *= ocelot_sb_pool[sb_index].cell_size;

        return 0;
}
EXPORT_SYMBOL(ocelot_sb_occ_tc_port_bind_get);

int ocelot_devlink_sb_register(struct ocelot *ocelot)
{
        int err;

        err = devlink_sb_register(ocelot->devlink, OCELOT_SB_BUF,
                                  ocelot->packet_buffer_size, 1, 1,
                                  OCELOT_NUM_TC, OCELOT_NUM_TC);
        if (err)
                return err;

        err = devlink_sb_register(ocelot->devlink, OCELOT_SB_REF,
                                  ocelot->num_frame_refs, 1, 1,
                                  OCELOT_NUM_TC, OCELOT_NUM_TC);
        if (err) {
                devlink_sb_unregister(ocelot->devlink, OCELOT_SB_BUF);
                return err;
        }

        ocelot->pool_size[OCELOT_SB_BUF][OCELOT_SB_POOL_ING] = ocelot->packet_buffer_size;
        ocelot->pool_size[OCELOT_SB_BUF][OCELOT_SB_POOL_EGR] = ocelot->packet_buffer_size;
        ocelot->pool_size[OCELOT_SB_REF][OCELOT_SB_POOL_ING] = ocelot->num_frame_refs;
        ocelot->pool_size[OCELOT_SB_REF][OCELOT_SB_POOL_EGR] = ocelot->num_frame_refs;

        ocelot_watermark_init(ocelot);

        return 0;
}
EXPORT_SYMBOL(ocelot_devlink_sb_register);

void ocelot_devlink_sb_unregister(struct ocelot *ocelot)
{
        devlink_sb_unregister(ocelot->devlink, OCELOT_SB_BUF);
        devlink_sb_unregister(ocelot->devlink, OCELOT_SB_REF);
}
EXPORT_SYMBOL(ocelot_devlink_sb_unregister);